Progress towards the rating-based achievements can backtrack, so losses feel exponentially worse and wins start to feel empty as you take one step forward and two steps back with each game played.
Quick matches are also the primary way people play Mahjong most days, with it being extremely rare to see a full match. Quick matches are much more luck-based on getting wins, as you can't play as defensively/strategically over a short match.
As an idea, something like "place first x times in player matches" would be a far better replacement for the rating-based achievements simply because achievement progress would then only be in a positive direction with no backtracking. Even something as time-consuming as 10~15 first-places for the orchestrion and 50 for the title/adventurer plate decorations would still be superior to the back-and-forth-but-mostly-backwards nightmare of playing against the rating system.
They wouldn't even have to replace the achievement requirement. They could simply add an alternative acquiring method like "Get a rating of 1600 or place first x times in player matches."
I just want to enjoy Doman Mahjong again while going after the achievements that they added themselves to attract people into playing Doman Mahjong in the first place. Mahjong is really fun, so please stop ruining it with rating.